There are two Popperian slogans which sum up the idea of conjecture. Conjecture is blind and There is no logic of discovery.
In essence, both assert that the formation of ideas and hypotheses is (shockingly) beyond philosophical judgement.
We may get our ideas because we read them in well respected college text books. Or we may receive our ideas from dreams. ConjectureIsBlind means that we can not distinguish between these two sources a priori. Sometimes the text books are wrong, and the dreams are right. (As in the case of Kekule dreaming the shape of the Benzine molecule.) Philosophy can't and shouldn't try to tell us which source is preferable.
This principle frees us in many ways.
It frees us from evaluating belief formation in terms of a belief's genealogy (RejectionOfJustification) and that in turn solves many problems. (EpistemologicalProblemsSolvedByCriticalRationalism)